1. Field of the Invention
The present invention relates to the magnetic coding of information on a film container and to camera apparatus adapted to respond to such information.
2. Discussion Related to the Problem
As disclosed in European Patent Application No. 0039492, published Nov. 11, 1981, it is known to provide a magnetic recording medium on a photographic film container for encoding information such as the number of film frames in the container, the photographic speed of the film, film type, and exposure latitude. The film container disclosed in the European application includes a disc of magnetic recording material that is attached to the end of a film spool. Information encoded on the disc is read out by rotating the disc past a magnetic read head when film is removed from the container.
Use of this technique requires relative movement between the magnetic disc and the read-head. The information must be memorized by the camera mechanism after each film advance and prior to the next camera actuation. In practice, weeks or months may pass between the last reading of the information and the next use of the information, so long-term memory or some other means must be provided to replenish the information prior to a subsequent actuation of the camera. Rather complex electronic circuitry comparable to that in a magnetic tape player must be provided in the camera to sense the magnetic information recorded on the disc. The magnetic information coded on the magnetic material is not available for use in lower-cost, non-electronic cameras.
The problem faced by the present inventors was to provide a means for magnetically encoding film related information on a film container that could be used by either a camera having electronic circuitry or a non-electronic camera.